1. Field of the Invention
The present invention relates generally to a heat sink, and more particularly to a heat sink comprising a plurality of individual fins assembled together for removing heat from a heat-generating electronic component to ambient environment.
2. Description of Related Art
Heat sinks are usually used to remove heat from heat-generating electronic components, such as central processing units (CPUs), power transistors, etc., to keep the components in stable operation. A typical heat sink comprises a base for contacting a heat-generating component to absorb heat generated by the heat-generating component and a plurality of parallel planar fins attached to the base by soldering or adhering. The fins are used for dissipating the heat to the ambient environment.
Typically, the heat sink is a parallel fin heat sink, which is fabricated by processes including an extrusion process, a gang sawing process and a bonding process. It is known that thickness and number of the fins produced by the extrusion process is restricted by the structure limitation and stress loading limitation of a die. If the number of the fins increases, the die fingers become weaker thus easily break off. Therefore, the extrusion process is not suitable for fabricating the high-density fin heat sink. The gang sawing process is performed by cutting off portions of a metal block to produce fins having predetermined thickness, number, depth and gap, which result in a great loss of material. In the bonding process, each fin is individually bonded into a base of the heat sink, which is time-consuming and labor intensive. In addiction, the fins that are not well-bonded into the base are likely to fall and thus be detached from the base.
A current thermal resolution to overcome the problems mentioned above is to provide a composite fin unit having a plurality of individual fins assembled together. The fins each have at least a flange extending perpendicularly from at least an edge thereof. Each flange of the fins is provided with a locking structure thereon. The locking structure of each fin engages with the locking structures of the rear and front fins to assemble the fins together with their flanges oriented in a same direction. The density of the fins can be predetermined by width of the flanges and able to be increased dramatically. However, the flanges of the fins are oriented in the same direction, one of the outmost fins would have its flange projecting nakedly from the fin unit. The naked flange is in a risk of damaging components surrounding the heat-generating component and hurting an operator during installation.
What is needed is a heat sink which has a plurality of individual fins assembled together to obtain a fin unit which has a high density of fins and is safe in installation and use.